Violin bow frog



April 19, 1960 R. L. STOVER 2,933,005

VIOLIN BOW FROG Filed March 14, 1958 i l VENTOR. 25] \a4 Patent o VIOLIN BOW FROG Roy L. Stover, Wichita, Kans.

Appiicatlon March 14, 1958, Serial No. '721,532

3 Claims. (Cl. 84--282) This invention relates generally to bows for any kind of a stringed musical instrument. More particularly it relates to the construction of a bow frog and a novel manner of anchoring the bow string or hairs to the frog.

With conventional frog constructions the re-stringing` or re-hain'ng of the bow is so intricate a procedure that it must be performed by a professional or highly skilled and experienced bow mechanic, else the frog may be damaged beyond repair.

It is a primary object of this invention to provide a frog in which an end of the hair or bow string is so easily anchored that the bow can be restrung in a matter of a few minutes by any performer or player who is capable of using a screw driver.

My frog construction eliminates the use of wedges to anchor the bow string in the frog, and thus eliminates the danger of splitting the frog. My construction eliminates the need for a reinforcing metal sleeve around that portieri of the frog from which the hairs emerge. lt also automatically combs or fans the grouped hairs at the point of emergency from the frog, thus eliminating the necessity of combing or flattening the grouped hairs with a separate tool or instrument. It provides a shape, balance and feel for the bow which is virtually identical to that provided by conventional bow frogs. It facilitates the shortening of the overall length of the bow string if such is desirable to better balance the bow for a particular piayer.

The invention together with other objects will be more clearly understood when the following description is read in connection with the accompanying drawings, in which:

Fig. l is a central longitudinal sectional view through a bow frog embodying my invention, the frog being shown installed on the aft or handle end of the bow stick;

Fig. 2 is an enlarged cross sectional view through a portion of the forward end of the frog, and is taken along the line 2 2 of Fig. l;

Fig. 3 is a perspective view of a string or hair anchoring plate which constitutes a part of the frog;

Fig. 4 is a bottom plan view of the frog of Fig. l, with the string anchoring plate and the locking plate removed; and

Fig. 5 is a bottom plan view of the frog with both the string anchoring and locking plates in operative position, and illustrates the manner in which the anchoring plate tlattens or fans the groups string hairs adjacent the point from which they emerge from the frog.

Referring to drawing Fig. l, the bow stick is designated by the numeral and the frog by the numeral 11. As is conventional the upper edge of the frog is provided with a groove to slidably fit the periphery of the stick near its aft end.

A large headed bolt 12 is threaded into the upper edge of the frog, and the bolt head is disposed in an elongated cavity in the bow stick. The bolt head is provided with a transverse screw threaded opening which receives the threaded portion 14 of a frog adjusting screw 15, the opposite ends of which are journaled in the bow stick as 2,933,005 Patented Apr. 19, i960 2 shown. The frog is conventionally recessed at its for'- ward end, at 16, and its general shape, size and weight is comparable to a conventional frog.

Specifically my invention relates Ito the construction which facilitates anchoring of the grouped or bunched bow string hairs in the frog. 1

To accomplish this a blind bore hole 17 is drilled into the frog from its lower edge. From this bore hole fore ward to the forward end 18 of the frog, its lower edge is grooved as at 19. The groove or trough is very sha1A low at the forward end of thefrog and increases com stantly in depth to its point of communication with hole ,-17. f

The side surfaces of the frog, along its lower edge, are respectively provided with elongated narrow grooves or ways 20 and 21 which are parallel to each other and to the lower edge surface of the frog. Their function is to slidably receive inturned opposed flanges 22 and 23 of a string anchoring plate '24, Fig. 3. This plate, as illustrated, is substantially G-shap'ed in cross section, and its bottom panel 25 is planar. At its aft end it has an integral stop flange 26. lts forward end is open and unobstructed.

Referring to Figs. l and 4, the aft end of the Ibottom edge of the frog is step cut as at '27 providing a shoulder 28 through which ways 20 and 21 extend. The depth of the step cut 27 is substantially 'equal to or a little greaterthan the height of stop ange 26 on anchor plate 24. Y A ya."

The frog is provided with a threaded hole 29 which receives a complementally threaded screw 30 which serves to hold a lock plate 31 (Figs. 1 and 5) on the step cut 27, which serves as a seat for the lock plate. Lock plate '31 serves to lock anchor plate 24 in a string anchoring position substantially covering trough 19.

String anchoring procedure Screw 30 and lock plate 31 are first removed from the frog. Anchor plate 2-4 is then moved aft in its ways until its forward end exposes the cavity formed by trough 19 and bore hole 17.

The bunched hairs at the aft end of the bow string are tightly wrapped or tied with suitable thread in the usual manner, as indicated at 32. The tied end is then inserted into bore hole 17 with the adjacent portion of the hairs disposed in trough 19. Due to the tightly bound condition of the hairs adjacent the thread 32 they virtually fill the bore hole 17 and the adjacent narrow portion of trough 19 near its aft end.

Anchor plate 24 is now moved forward in its ways and the forward portion of its bottom panel 25 compresses the hunched hairs against the bottom of trough 19. As the forward end of panel 25 approaches the forward end 18 of the frog the bunched hairs are forced to atten out or fan into a very thin layer, as clearly shown at 33 in Figs. 2 and 5. The hairs of the string are thus automatically arranged in the at cross sectional shape desired by the player of the instrument. Furthermore, due to the wedging of the bunched hairs into the narrowing trough, the anchor plate 24 firmly holds the aft end of the bow string, without danger of its subsequently loosening in the frog.

Forward movement of anchor plate '24 on the frog is of course, limited by contact -of stop ange 26 on shoulder 28, as shown in Fig. 1. Lock plate 31 is then secured on its seat 27 by screw 30 and the string anchoring process is complete. The anchored end of the bow string may be removed from the frog by reversing the above described procedure. It will be understood that the cav ity formed by the trough l19 and hole 17 may be varied in size and shaped to accommodate the particular type of `stringbeing used, and to accommodate the tied'end of the string.

Having described the invention with suiicient clarity i hunched ends of the bow string strands, anda longitudinally disposed `string nesting trough extendingrfrom'the forward end of the body aft to openly communicate with the lopen end of said bore hole, said trough decreasing in width and increasing in depth from its' forward end aft; and a string anchoring plate secured to the lower edge portion of said body for slidable movement there# along to a position overlying both the trough and bore hole portions of the string cavity, the depth of the trough portionfof the cavity being such that the bunched ends of the bow string strands are compressed and wedged therein when the plate is moved tothe mentioned position, thus fanning and tightly anchoring the bow string strands Within the frog in the absence of a wedging block or other string end wedging means. I 4

. 2. The frog described in claim 1, and lmeans for locking said anchor plate in a string anchoring position on the lower edge of said body.

41 3. A bow frog comprising: an. elongated body' which is generally rectangular in cross section; means. for adjustably securing theupper longitudinal edge of said body to a bow stick; a string receiving cavity extending inward into said body from its lower edge surface, said cavity including an elongated longitudinally disposed generally wedge shaped trough extending from the forward end of the lower edge of said body to a point intermediate its ends, said trough increasing gradually in depth and decreasing gradually in width from its forward end toward its aft end, said cavity including a bow string end receiving blind bore hole extending transversely inward into said body from its lower edge surface and openly communicating with the aft end of said trough; opposed slideways extending along ythe lower edge of .said body and into the opposite side surfaces thereof; and an elongated anchor plate having inturned side edges slidably received in the respective slideways and movable therealong to a position overlying both the trough and bore hole portions of the string cavity, the distance between the plate and the trough bottom, when the plate is in the mentioned position, being such that the cavity enclosed strands of the bow string end are tanned and `tightly wedged betweeny them, thus firmly anchoring the Ibow string end in the frog in the absence of a wedging block or other string end wedging means. t y

References Cited in the le of this patent UNITED STATES PATENTS Great Britain Aug. 16, 1923 

